what are you doing today?

[Mad Mat]

Im post matching my bpt head today and also found out this too.

THERE IS A MOTHER ****ING SHORT NOSE CRANK IN MY BPT...


AAAAAAAAAAAAAAAA
(throws hands in the air and kicks block)

[TheMAN]

GAHAHAHHAHA
so take the crank from one of your BA BPs and throw the bish in with new bearings... buy a new oil pump from an NB2 and drill the hole for the dipstick tube... just don't pull the pistons out or disturb their positions

well worth it!

[HAIGHIE]

Originally Posted by Mad Mat

hands in the air and kicks block)

haha i can imagine you doing this lol,

well do what ed said ^^^^

[phildough]

Kicking the block will get you nowhere but hospital with a broken toe.
Personally I think swapping the cranks is a better idea.

[Mad Mat]

Originally Posted by HAIGHIE

haha i can imagine you doing this lol,

well do what ed said ^^^^

Yer i am, i have a gtr crank and a na crank at home. Will be throwing in the na pistons too as there just sitting here. Cant hurt to increase cr a little right

[TheMAN]

then why bother
just use the entire NA block

if you remove the pistons, you'll need to rehone the cylinders and buy new rings
rings are runned in and stayed in position for proper seal... removing pistons will stuff that up!

crank in the GTR is the same as any BP, nothing special about it

[Mad Mat]

Originally Posted by TheMAN

then why bother
just use the entire NA block

if you remove the pistons, you'll need to rehone the cylinders and buy new rings
rings are runned in and stayed in position for proper seal... removing pistons will stuff that up!

crank in the GTR is the same as any BP, nothing special about it

Yer the pistons have been removed already out of the NA block. The NA block dodnt have the oil and water supply points in the exhaust face/side of the block(mazda must have revised the bp series 3 blocks) im already getting the block rehonned and i have ordered new rings and bearings too. Its a total revuild but with NA pistons rods, crank, bpt block, bpt head, NA cams, port matched head and manifolds.

[Cosmo Dude]

Originally Posted by TheMAN

then why bother
just use the entire NA block

if you remove the pistons, you'll need to rehone the cylinders and buy new rings
rings are runned in and stayed in position for proper seal... removing pistons will stuff that up!

crank in the GTR is the same as any BP, nothing special about it

Interesting you say the cranks are the same. Mazda GTR suppliment tells another story.
Who should be believed??? I'll take the word of the Mazda manual over some loud mouth seppo any time!!!!

[Mad Mat]

Originally Posted by Cosmo Dude

Interesting you say the cranks are the same. Mazda GTR suppliment tells another story.
Who should be believed??? I'll take the word of the Mazda manual over some loud mouth seppo any time!!!!

i have a gtr crank at home. and yes they are interchangable but the crank on the gtr has a different spacing for the crank bolts to the flywheel. so u cant just bolt a gtx fly wheel to it and be done...

[TheMAN]

Originally Posted by Cosmo Dude

Interesting you say the cranks are the same. Mazda GTR suppliment tells another story.
Who should be believed??? I'll take the word of the Mazda manual over some loud mouth seppo any time!!!!

which GTR supplement do you have? mine says it is the same as the GTX one (of the SAME year)
the JDM and EDM BG2 parts catalogues also show no difference between NA, GTX, or GTR as far as BG2 BP crankshafts... yes, GTX models did exist as BG2s, just not talked about often, but they do exist... there are no BG1 GTRs, so if you think they exist, then I have a bridge to sell you

the ONLY bottom end parts that are different in the GTR compared to other BG2 BPs are the rods, pistons, and piston rings... the parts catalogues says so, and the manual says so

the GTR crank is just a long nose crankshaft, nothing more... it is the same as all the BG2 turbo (GTX) or non-turbo BP crankshafts... the same crankshaft continued to be used in the BA, NA2, and all the way till NB production ended

even if the manual is wrong, why would the parts catalogues be wrong? they're updated monthly during vehicle production and periodically afterwards, unlike shop manuals... the updates corrects errors and also supersedes whatever outdated or discontinued parts with new ones or substitutions.... so what should I believe more? parts catalogues or shop manuals?


why the adversity?

[TheMAN]

Originally Posted by Mad Mat

i have a gtr crank at home. and yes they are interchangable but the crank on the gtr has a different spacing for the crank bolts to the flywheel. so u cant just bolt a gtx fly wheel to it and be done...

how so? as I said, all long nose BP crankshafts are the same turbo or non-turbo, and all short nose BP crankshafts the same turbo or non-turbo.... there's only two different BP crankshafts... the short nose and the long nose.... based on that information:
the N/A flywheel was never changed during the whole BG production... the crankshaft did during mid production of BG1s, as we already know, and so did the oil pump for compatibility reasons with the long crankshaft nose design

the GTR shop manual supplement also shows the flywheels to be interchangeable between the (BG2) GTX and GTR.... parts catalogue shows them in fact to be the same!

[Clean_Cookie]

What's this whole advantage with different cranks? Just add another psi and come out the same?

[TheMAN]

I guess you didn't learn about why the short nose crank is crap and everyone should avoid using it!
http://www.miata.net/garage/crankshaft.html

[Clean_Cookie]

Every motor I've ever had has only had the 4 small bolts and the smaller pulley on the front. Any idea on which motors in the BA series (if any) have these large nose cranks? Is it really worth pulling out another one, especially when the engine comes with a good warranty for 18mths/unlimited kms, if its going to fail, a year of abuse would do it I'd think?

[TheMAN]

all BAs have the long nose cranks... as I said, Mazda went to the long nose crank during mid production of the BG1, long before the BA ever came out
all crank pulleys have 4 bolts, long or short crank nose

as shown on that page I linked, the slots in the pulleys are the easy quick identifiers of which crank is used on a MX-5, but it might not be true on a BG

[Clean_Cookie]

Right. So how the hell did mat end up with a shortnose from his s3 ba motor. If you're not doing anything but headwork, would you not be better off to just swap heads, add turbo to original motor? No engine removal etc. Run an oil relocation kit and add gtx sump?

Just seems like a days worth of work vs a weekend.

[TheMAN]

didn't he say he has a short nose crank BPT? meaning he got an early GTX engine?

the other easy way to identify if you have short or long nose crank are the oil pump stampings... B660 = short nose crank, B6S8 = long nose crank

[Clean_Cookie]

I'll head over to the engine builders to get them the last few parts I got and see what I've got. I'm not fussed tbh. Maybe when it breaks down on the road.

Btw, thanks for the info!

[TheMAN]

you got a new NB2 oil pump, so your only choice now is to use a long nose crank
if you've been using your BA parts, it should all work no problem

[project.r.racing]

wow that got more exciting than it needed to be. as edwin said. with a full parts supply at hand, i dont see what the problem is.